94 citations · 301 across the 16 of their papers we have counts for
16 papers
Influence of disorder at Insulator-Metal interface on spin transport
Mahsa Seyed Heydari, Wolfgang Belzig, Niklas Rohling
Motivated by experimental work showing enhancement of spin transport between Yttrium Iron Garnet and Platinum by a thin antiferromagnetic insulator between them, we consider spin t…
Dipole-dipole-interaction-induced entanglement between two-dimensional ferromagnets
Dennis Wuhrer, Niklas Rohling, Wolfgang Belzig
We investigate the viability of dipole-dipole interaction as a means of entangling two distant ferromagnets. To this end we make use of the Bogoliubov transformation as a symplecti…
Discovery of an exchange-only gate sequence for CNOT with record-low gate time using reinforcement learning
Violeta N. Ivanova-Rohling, Niklas Rohling, Guido Burkard
Exchange-only quantum computation is a version of spin-based quantum computation that entirely avoids the difficulty of controlling individual spins by a magnetic field and instead…
Even-odd effect for spin current through thin antiferromagnetic insulator
Niklas Rohling, Roberto E. Troncoso
Magnon spin transport in a metal-antiferromagnetic insulator-ferromagnetic insulator heterostructure is considered. The spin current is generated via the spin Seebeck effect and in…
Optimal Quantum State Tomography with Noisy Gates
Violeta N. Ivanova-Rohling, Niklas Rohling, Guido Burkard
Quantum state tomography (QST) represents an essential tool for the characterization, verification, and validation (QCVV) of quantum processors. Only for a few idealized scenarios,…
Theory of quantum entanglement and the structure of two-mode squeezed antiferromagnetic magnon vacuum
Dennis Wuhrer, Niklas Rohling, Wolfgang Belzig
Recent investigations of the quantum properties of an antiferromagnet in the spin wave approximation have identified the eigenstates as two-mode squeezed sublattice states. The uni…
Quantum state tomography as a numerical optimization problem
Violeta N. Ivanova-Rohling, Guido Burkard, Niklas Rohling
We present a framework that formulates the quest for the most efficient quantum state tomography scheme as an optimization problem which can be solved numerically. This approach ca…
Superconductivity at metal-antiferromagnetic insulator interfaces
Eirik Løhaugen Fjærbu, Niklas Rohling, Arne Brataas
Magnons in antiferromagnetic insulators couple strongly to conduction electrons in adjacent metals. We show that this interfacial tie can lead to superconductivity in a tri-layer c…
Optimal choice of state tomography quorum formed by projection operators
Violeta N. Ivanova-Rohling, Niklas Rohling
A minimal set of measurement operators for quantum state tomography has in the non-degenerate case ideally eigenbases which are mutually unbiased. This is different for the degener…
Superconductivity Induced by Interfacial Coupling to Magnons
Niklas Rohling, Eirik Løhaugen Fjærbu, Arne Brataas
We consider a thin normal metal sandwiched between two ferromagnetic insulators. At the interfaces, the exchange coupling causes electrons within the metal to interact with magnons…
Electrically Driven Bose-Einstein Condensation of Magnons in Antiferromagnets
Eirik Løhaugen Fjærbu, Niklas Rohling, Arne Brataas
We explore routes to realize electrically driven Bose-Einstein condensation of magnons in insulating antiferromagnets. Even in insulating antiferromagnets, the localized spins can…
Optimizing electrically controlled echo sequences for the exchange-only qubit
Niklas Rohling, Guido Burkard
Recently, West and Fong [New J. Phys. 14, 083002 (2012)] introduced an echo scheme for an exchange-only qubit, which relies entirely on the exchange-interaction. Here, we compare t…
Hybrid spin and valley quantum computing with singlet-triplet qubits
Niklas Rohling, Maximilian Russ, Guido Burkard
The valley degree of freedom in the electronic band structure of silicon, graphene, and other materials is often considered to be an obstacle for quantum computing (QC) based on el…
Tomography scheme for two spin-1/2 qubits in a double quantum dot
Niklas Rohling, Guido Burkard
We present a scheme for full quantum state tomography tailored for two spin qubits in a double quantum dot. A set of 15 quantum states allows to determine the density matrix in thi…
Universal Quantum Computing with Spin and Valley
Niklas Rohling, Guido Burkard
We investigate a two-electron double quantum dot with both spin and valley degrees of freedom as they occur in graphene, carbon nanotubes, or silicon, and regard the 16-dimensional…
Optimization of electron pumping by harmonic mixing
Niklas Rohling, Frank Grossmann
For a symmetric bridge coupled to infinite leads, in the presence of a dipole-coupled external ac-field with harmonic mixing, we solve the Schrödinger equation in the time-domain u…